Most of my work is auto restoration/modification. Besides saws and lots of cut off tools, I have an oxy acetylene rig and a plasma cutter. I don't use either frequently but I use the oxy acetylene 2-3 times as much. When I need it, the plasma is good to have. When you need to heat something up...
I restore old cars and put updated suspension and drivetrain in them. These are cars with a solid rear axle, so only a front end alignment is needed and lots of these cars have wheel wells that make it difficult to mount the 4 required alignment sensors that come on today's alignment machines...
Like Robert, if I'm not interested in saving the panel, I grind it out with a cutoff wheel or air file. If I'm trying to save it, I drill it with different tools depending on the job.
I've had several Dremel tools over the years and most of my work is in metal. When I bought my last one, I bought the heavy duty model. It is heavier but it is more to my needs in mettal work.
https://www.dremel.com/us/en/p/4000-2-32-f0134000fb
I think one of the reasons lots of people complain about short life on these bits is that they spin them too fast and burn them up. Once the first step penetrates, I slow the bit down. I get pretty good life out of mine.
Definitely need to take the weight of the motor off the shaft/coupling. Some sort of foot bracket that can be shimmed is commonly used. Misalignment will eventually break the shaft. A Lovejoy/Magnalloy type coupling is more forgiving than the chain and sprocket type...